ABSTRACT
Certain 1-[4-chlorophenyl]-4-hydroxy-1H-pyrazole-3-carboxylic acid hydrazide derivatives, carrying various substituents at position 3- such as 1,2,4-triazolyl and 1,2,4-oxadiazolyl moieties have been previously synthesized and preliminarily evaluated for their antitumor activity at the National Cancer Institute's [NCI] in vitro disease-oriented antitumor screen unit. In the primary 60 cell line assay, three compounds [1-3] revealed potential broad spectrum antitumor activity against a wide range of different human cell lines of nine tumor subpanels. These compounds were further selected by the NCI for carrying out confirmatory screening procedures in order to assess their exact in vitro antitumor potentialities. A detailed discussion of the best in vitro antitumor results of these active analogs obtained from the three consecutive NCI procedures is reported in this paper. The active three compounds at the GI50 level exhibited TGI and LC50 levels with nearly the same order of activity; 3> 2> 1